Microvessel density in chemosensitive and chemoresistant diffuse large B-cell lymphomas

Preliminary reports involving a number of different kinds of tumors have in dicated that microvessel quantification may be useful in predicting disease outcome. The aim of this study was to examine the relationship between mic rovessel density (MVD) as a parameter of tumor angiogenesis and the respons e to chemotherapy in diffuse large B-cell (DLBC) lymphomas. A total of 36 DLBC lymphoma patients were evaluated, 23 of them with a chem osensitive; responsive disease (median survival 8 y) and 13 with a chemores istant, refractory disease (median survival 8 months). Microvessel quantifi cation was performed by immunohistochemical staining, using monoclonal anti bodies against factor VIII related antigen (F8RA) and against pratelet/endo thelial cell adhesion molecule-CD31. We found that F8RA stained a significantly higher number of blood vessels ( about 2.5 times more) than CD-31; 7 samples were not stained with CD-31 but were positive for F8RA. There was no significant difference between the de nsity of microvessel staining of the two groups. In the chemosensitive DLBC lymphomas positive for F8RA, the mean number of microvessels stained was 5 4.5+/-36.1 per microscopic field (200x) examined (range 6-149) whereas in t he chemoresistant group the corresponding mean number was 43.1+/-25.5 (rang e 11-94). F8RA appears to be more sensitive for staining DLBC lymphomas microvessels than CD-31. Our data demonstrate that there is no correlation between tumor MVD and response to chemotherapy in patients with DLBC lymphomas.